#!/usr/bin/env python
#
# Serial port enumeration. Console tool and backend selection.
#
# This file is part of pySerial. https://github.com/pyserial/pyserial
# (C) 2011-2015 Chris Liechti <cliechti@gmx.net>
#
# SPDX-License-Identifier:    BSD-3-Clause

"""\
This module will provide a function called comports that returns an
iterable (generator or list) that will enumerate available com ports. Note that
on some systems non-existent ports may be listed.

Additionally a grep function is supplied that can be used to search for ports
based on their descriptions or hardware ID.
"""

import sys
import os
import re

# chose an implementation, depending on os
#~ if sys.platform == 'cli':
#~ else:
if os.name == 'nt':  # sys.platform == 'win32':
    from serial.tools.list_ports_windows import comports
elif os.name == 'posix':
    from serial.tools.list_ports_posix import comports
#~ elif os.name == 'java':
else:
    raise ImportError("Sorry: no implementation for your platform ('{}') available".format(os.name))

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


def grep(regexp):
    """\
    Search for ports using a regular expression. Port name, description and
    hardware ID are searched. The function returns an iterable that returns the
    same tuples as comport() would do.
    """
    r = re.compile(regexp, re.I)
    for info in comports():
        port, desc, hwid = info
        if r.search(port) or r.search(desc) or r.search(hwid):
            yield info


# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
def main():
    import argparse

    parser = argparse.ArgumentParser(description='Serial port enumeration')

    parser.add_argument(
        'regexp',
        nargs='?',
        help='only show ports that match this regex')

    parser.add_argument(
        '-v', '--verbose',
        action='store_true',
        help='show more messages')

    parser.add_argument(
        '-q', '--quiet',
        action='store_true',
        help='suppress all messages')

    parser.add_argument(
        '-n',
        type=int,
        help='only output the N-th entry')

    args = parser.parse_args()

    hits = 0
    # get iteraror w/ or w/o filter
    if args.regexp:
        if not args.quiet:
            sys.stderr.write("Filtered list with regexp: {!r}\n".format(args.regexp))
        iterator = sorted(grep(args.regexp))
    else:
        iterator = sorted(comports())
    # list them
    for n, (port, desc, hwid) in enumerate(iterator, 1):
        if args.n is None or args.n == n:
            sys.stdout.write("{:20}\n".format(port))
            if args.verbose:
                sys.stdout.write("    desc: {}\n".format(desc))
                sys.stdout.write("    hwid: {}\n".format(hwid))
        hits += 1
    if not args.quiet:
        if hits:
            sys.stderr.write("{} ports found\n".format(hits))
        else:
            sys.stderr.write("no ports found\n")

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# test
if __name__ == '__main__':
    main()